The invention relates to a laser microscope for examining a sample. The laser microscope has a laser light source which generates laser light pulses. An optical element disperses the spectrum of the laser light pulses. The latter are termed broadband laser light pulses below.
Pulsed laser light is usually used in laser microscopes for measuring intracellular ion concentrations. In this case, the process is based on the discovery that the fluorescence lifetime—that is, the average duration for which the electrons remain in the excited state—changes with ion concentration. A corresponding method is, for example, fluorescence lifetime imaging (FLIM). The pulse durations of the laser light pulses necessary in this case are in the range of picoseconds, for example.
For the purpose of examining the fluorescence lifetime of different dyes, the sample must frequently be excited with laser light pulses of varying wavelength. For this purpose, various lasers are provided which each generate laser light pulses of one wavelength or of a very small wavelength region. Due to the different propagation speeds of laser light of different wavelengths in media, resonators in laser light sources commonly have compensation elements which function to make the laser light pulses of differing wavelengths leave the laser at the same time. The time spans being compensated in such cases are in the range of femtoseconds.
U.S. Pat. No. 5,995,281 (=DE 196 22 359) discloses a device for coupling the beam of short-pulse lasers into a microscopic beam path, wherein the coupling is achieved by at least one fiber optic waveguide arranged downstream from the laser.
German patent no. DE 103 13 987 B4 discloses a device for illuminating an object. The light of a light source is coupled into a micro-structured element which disperses the spectrum of the light.
U.S. Pat. No. 7,995,271 (=EP 1 986 030) discloses a laser microscope which has a laser light source. The laser light is coupled into a first and a second fiber optic waveguide.